US2739884A - Apparatus for mixing fluids - Google Patents

Description

March 27, 1956 F. E. DAVIS 2,739,884

APPARATUS FOR MIXING FLUIDS Filed Sept. 25 1953 2 Sheets-Sheet 1 F IEIl- Fmm f. flflV/f,

March 1956 F. E. DAVIS I 2,739,884

APPARATUS FOR MIXING FLUIDS Filed Sept. 25, 1953 2 Sheets-Sheet 2 1710672109! Ham 5 z74v/5,

United States Patent 9 APPARATUS FOR MIXING FLUIDS Floyd E. Davis, Gary, Ind., assignor to United States Steel Corporation, a corporation of New Jersey Application September 25, 1953, Serial No. 382,359

4 Claims. (Cl. 48-180) This invention relates to an improved device for mixing fluids in relatively large conduits.

One purpose for which my device is especially suited is for introducing an enriching gas to another gas carried in a main. For example, blast furnace gas has a relatively low calorific value (approximately 90 B. t. u. per cu. ft.), and before it is used for some purposes, it is enriched by addition of gas of higher calorific value, such as coke oven gas (approximately 550 B. t. u. per cu. ft.). Such additions conveniently are made in the blast furnace gas main, which may be feet or more in diameter. For proper utilization the gases must be mixed intimately to produce a uniform product, and the calorific value of the product must be controlled carefully. Nevertheless it is apparent that the invention is not restricted to this particular application.

An object of the invention is to provide an improved mixing device which assures that the added fluid is mixed thoroughly with the fluid already in the mixing space, and which facilitates controlling the amount of fluid added.

A further object is to provide, in combination with a large diameter conduit, an improved fluid adding and mixing device which distributes the added fluid over the full cross section of the conduit and thus enables this fluid to mix intimately into the fluid already in the conduit in a relatively short distance.

A more specific object is to provide, in combination with a large diameter conduit, an improved fluid mixing and adding device which includes a plurality of radial feeding pipes extending into the conduit in a common plane and spaced uniformly around its circumference, said pipes having discharge openings facing in the upstream direction and being of an area proportioned to the area they serve in the conduit.

In accomplishing these and other objects of the invention, I have provided improved details of structure, a preferred form of which is shown in the accompanying drawings, in which:

Figure .l is a longitudinal section through a conduit equipped with a mixing device embodying features of my invention;

Figure 2 is a cross section on line II-II of Figure 1;

Figure 3 is a longitudinal section on a larger scale on line III-III of Figure l; and

Figure 4 is a cross section on a larger scale illustrating the different zones in the conduit.

Figures 1 and 2 show a relatively large diameter fluid conduit 10, for example a blast furnace gas main. The fluid travels in the direction indicated by the arrow in Figure 1. In accordance with my invention, a plurality of feeder pipes 12, in this instance six, extend through the wall of the conduit. These pipes are spaced uniformly around the circumference of the conduit and they extend radially thereof and terminate adjacent the central axis. The axes of the pipes occupy a common plane which is perpendicular to the axis of the conduit. Each pipe 12 has a discharge slot 13 which faces in thfeupstream direction of the conduit; The" slots 13' extend These inner ends preferably taperand are closed, so that all discharge is throughtheslo'ts 13'. The" outer en'ds' of' the pipes 12 areconne'ctedto a supply line 14th'rough suitable connecting pipes 15. The supply line carries a fluid to be added to that in the conduit, for example coke oven gas.

To obtain proper mixing of the two fluids, the width of each discharge slot 13 increases along its length outwardly from the central axis of the conduit 10. The change is such that the slot area remains approximately proportional to the cross sectional area of the portion of the conduit which it serves. In Figure 4 I have shown the cross section of the conduit divided into four concentric zones A, B, C and D. The slot 13 is narrowest in the central zone A and becomes progressively wider in steps in the zones B, C and D which have greater cross sectional area. Nevertheless it is apparent that equivalent proportioning could be obtained with uniformly tapered slots.

Since the slots 13 discharge upstream of the conduit 10, the flow of added fluid immediately adjacent these slots is counter to that of the fluid already in said conduit. Nevertheless the latter is much more voluminous and it sweeps the added fluid around the pipes 12, somewhat as indicated in Figure 3. intimately, and a short distance beyond the pipes 12 the mixture becomes uniform. The mixture can be sampled at any location along the conduit after it has become uniform, and the amount of added fluid can be controlled through suitable valves in the supply line 14 to furnish a mixed product of the desired composition.

While I have shown and described only a single em bodiment of the invention, it is apparent that modifications may arise. Therefore, I do not wish to be limited to the disclosure set forth but only by the scope of the appended claims.

I claim:

1. The combination, with a conduit of relatively large diameter and having upstream and downstream directions and being adapted to carry a relatively large volume of fluid in the latter direction, of a device for adding a relatively small volume of fluid to that already in the conduit comprising a plurality of uniformly spaced radial feed pipes extending into said conduit, said pipes having discharge openings facing in the upstream direction of said conduit counter to the direction of flow of fluid in the latter and being otherwise closed, said openings furnishing larger discharge areas adjacent the walls of said conduit than adjacent the central axis, and means for introducing fluid to said pipes, said conduit extending beyond said pipes in the downstream direction to allow the two fluids to form a uniform mixture therein.

2. A combination as defined in claim 1 in which said pipes extend from the walls of said conduit to adjacent the central axis thereof and the axes of said pipes occupy substantially a common plane perpendicular to the central axis of said conduit.

3. A combination as defined in claim 2 in which said discharge openings are in the form of slots of increasing width outwardly from the center of said conduit to proportion their area to that of the portion of said conduit which they serve.

4. The combination, with a large diameter gas main having upstream and downstream directions and adapted to carry gas of low calorific value toward the latter direction, of a device for adding an enriching gas of higher calorific value and intimately mixing the two gases immediately beyond the place of addition comprising a Consequently the two fluids mix plurality of uniformly spaced radial pipes extending from the walls of said main inwardly to adjacent the central axis thereof, said pipes having elongated continuous discharge openings facing in the upstream direction of said,

main counter to thedirection of flow of the gas of 10W calorific value and being otherwise closed, said openings providing a greater discharge area adjacent the Walls of said main than adjacent the central axis, and means for introducing an enriching gas to said pipes.

UNITED STATES PATENTS Great Britain Oct. 15, 1913

Claims (1)

1. THE COMBINATION, WITH A CONDUIT OF RELATIVELY LARGE DIAMETER AND HAVING UPSTREAM AND DOWNSTREAM DIRECTIONS AND BEING ADAPTED TO CARRY A RELATIVELY LARGE VOLUME OF FLUID IN THE LATTER DIRECTION, OF A DEVICE FOR ADDING A RELATIVELY SMALL VOLUME OF FLUID TO THAT ALREADY IN THE CONDUIT COMPRISING A PLURALITY OF UNIFORMLY SPACED RADIAL FEED PIPES EXTENDING INTO SAID CONDUIT, SAID PIPES HAVING DISCHARGE OPENINGS FACING IN THE UPSTREAM DIRECTION OF SAID CONDUIT COUNTER TO THE DIRECTION OF FLOW OF FLUID IN THE LATTER AND BEING OTHERWISE CLOSED, SAID OPENINGS FURNISHING LARGER DISCHARGE AREAS ADJACENT THE WALLS OF SAID CONDUIT THAN ADJACENT THE CENTRAL AXIS, AND MEANS FOR INTRODUCING FLUID TO SAID PIPES, SAID CONDUIT EXTENDING BEYOND SAID PIPES IN THE DOWNSTREAM DIRECTION TO ALLOW THE TWO FLUIDS TO FORM A UNIFORM MIXTURE THEREIN.

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